Cutless rotary arc gap switch and dual triggering system

ABSTRACT

A rotary arc gap (RAG) switch capable of handling large amounts of current flow is disclosed. The circular electrodes of the switch incorporate the use of a high-resistance material placed in a gap in the electrodes. The absence of an air gap in the electrodes reduces wear and broadening at the edges of the gap and thus improves the life span of the switch. Further disclosed is the use of a dual trigger mechanism that also improves the life span of the electrodes and the triggers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application represents the national stage filing under 35 U.S.C.§371 of, and claims priority to, international (PCT) applicationPCT/KR99/00649, filed Oct. 28, 1999, which claims priority to Koreanpatent application 1999-1975, filed Jan. 22, 1999.

FIELD OF THE INVENTION

The present invention relates to a rotary arc gap (RAG) switch and atriggering system used in the switch. More particularly, the presentinvention relates to a cutless RAG switch wherein a high resistancematerial, instead of an air gap, is inserted into the electrodes of aRAG switch. Further, it relates to a dual triggering system wherein twotriggers are used for the cutless RAG switch.

BACKGROUND OF THE INVENTION

A RAG switch is a switch that can withstand a great amount of currentflow. Generally speaking, and referring to FIGS. 1 and 2, the switchcomprises an upper circular electrode 1 connectable to a power supply,and lower circular electrode 2 connectable to a load. The switchgenerally controls the direction of current flow by forming a cut in theelectrodes 1 and 2. To elaborate, an arc 5 revolves on an infinitetrajectory due to the electromagnetic energy that is generated by thepassage of current through the switch. The revolving arc 5 prevents theelectrodes from becoming damaged when compared with a static arc thatremains in one position. Therefore, the life span of the switch ismaximized. In the prior art, and referring to FIG. 1, cuts are made inthe electrodes to control the direction of current flow, such cutsconstituting air gaps in the electrodes. The structure of conventionalRAG switch electrodes 1 and 2 are shown in FIG. 1 in both planar andcross-sectional views.

However, in the prior art electrode structures involving the use of airgaps, as shown in FIG. 1, the velocity of arc 5 becomes slow at thecorner section of the cut, thereby causing the structure of the cuts towear and broaden, especially at the sharp edges of the cut.Consequently, the life span of the switch is shortened.

Additionally, another problem exists in the prior art in that the lifespans of triggers and electrodes of the conventional triggering systemused in the switch electrodes are reduced due to the use of only asingle trigger.

SUMMARY OF THE INVENTION

The present invention solves the aforementioned problems. To prolong thelife span of a RAG switch and to prevent wear and broadening at the airgaps cuts, a high resistance material is inserted into the cut of theswitch electrodes. Additionally, the disclosed switch employs a dualtriggering system using two triggers for the switch electrodes, therebyprolonging the life spans of triggers and switch electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows cross-sectional and planar views of the electrodes of aconventional RAG switch utilizing air gap cuts.

FIG. 2 shows perspective and side view of a preferred embodiment of thecutless RAG switch of the present invention.

FIG. 3 shows cross-sectional and planar views of the electrodes of theswitch of FIG. 2 and shows the use of dual triggers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 2 shows the construction of a cutless RAG switch according to anembodiment of the invention. The switch comprises an upper circularelectrode 1 connectable to a power supply, and a lower circularelectrode 2 connectable to a load which is separated from the upperelectrode 1 by a certain distance. The first and second circularelectrodes 1, 2 are concentric around an axis 15, which is perpendicularto the planar surfaces 11, 12 of each respective electrode. Alsoincluded is a primary high-resistance material 3 that is inserted into acut in the lower electrode 2. A primary trigger 4 also is installed onthe lower electrode 2 and disposed at a certain angle to said primaryhigh-resistance material 3. A secondary high-resistance material 3 isinserted into a cut in the upper electrode 1, which is displaced at anangle of 180° relative to the primary high-resistance material 3 of thelower electrode 2.

The upper and lower electrodes 1 and 2 are positioned at a distance ofapproximately 10 millimeters from each other. As explained earlier, theupper electrode 1 is connected to a power supply (capacitor bank), andthe lower electrode 2 is connected to a load. The primary and secondaryhigh-resistance materials 3 are installed in the lower electrode 2 andthe upper electrode 1 respectively. When the trigger is applied at adesired time, an arc 5 is formed between the upper electrode 1 and thelower electrode 2, thereby allowing the current to flow. The primaryhigh-resistance material 3 of the lower electrode 2 can be inserted intoany position of the electrode, but the secondary high-resistancematerial 3 of the upper electrode 1 should be so inserted at an angle of180° with respect to the primary high-resistance material 3.

The materials for the primary and secondary high-resistance materials 3can be alloys of iron and nickel, or alloys of iron and chromium. Thespecific constituents and the properties of such suitable alloys areprovide in the below tables:

TABLE 1 Temperature Name Constituent Volume Coefficient of Tensile of(%) Resistance Resistance Strength Density Alloy Fe Ni (μΩcm) (× 10⁴)(kg/mm²) (g/cm³) Climax 75 25 83.1   9.8 — 8.14 Phenix 75 25 83.1 11 498.10 Imvar 64 36 78˜85 12 98 8.12

TABLE 2 Constituent Volume Temperature Coefficient Tensile (%)Resistance of Resistance Strength Class Cr Al Mn C Fe (μΩcm) (× 10⁴)(kg/mm³) Fe Cr 23˜36 4˜6 1.0 or 0.15 or Rest 132˜248 1.0 or less 1.0 orless 70 or more Class 1 more less (200˜400° C.) (20˜100° C.) Fe Cr 17˜212˜4 1.0 or 0.15 or Rest 115˜129 2.5 or less 2.5 or less 60 or more Class2 more less (200˜400° C.) (20˜900° C.)

The primary trigger 4 is installed at a position on the lower electrode2 that is equal to or greater than 30° from the location of the primaryhigh-resistance material 3. The primary trigger 4, preferably tungsten 7wrapped with teflon 6, generates an arc by operating at an desired time.

FIG. 3 shows cross-sectional and planar views of a cutless RAG switchthat uses two triggers 4 and 8 according to the present invention. Asshown in FIG. 3, the additional secondary trigger 8 is installed at anangle of 180° relative to the primary trigger 4. As mentioned before,the primary trigger 4 is inserted into the lower electrode 2 at an angleof 30° or more relative to the high-resistance material 3 of the lowerelectrode 2.

If the arcs 5 are generated at both the primary and secondary triggers 4and 8, the current flows in a dispersed manner, and consequently, thelife spans of electrodes are prolonged. If an arc 5 is generated ateither one of the primary or secondary triggers 4 and 8, it isequivalent to the case in which a single trigger is used. Nevertheless,in this latter case, since an arc will be produced at either one of thetriggers 4 or 8, the same amount of a trigger action can be generatedwhen compared with a single trigger device while prolonging the lifespan of either triggers 4 and 8. In other words, the life span of a RAGswitch can be prolonged because the life spans of electrodes and triggerelectrodes are extended via the system as illustrated in FIG. 3.

In accordance with the disclosed embodiments, the life span of a RAGswitch can be prolonged by preventing wear and broadening of the cut ofan electrode though the insertion of a high-resistance material in thecut of the electrodes of conventional RAG switches. Further, the lifespans of electrodes and trigger electrodes of RAG switches can beextended by virtue of the introduction of a dual triggering system.

What is claimed is:
 1. A rotary arc gap switch, comprising: a firstcircular electrode connectable to a power supply, wherein the firstcircular electrode is concentric about an axis that is perpendicular toa plane defined by the first circular electrode; a second circularelectrode connectable to a load, the first circular electrode beingseparated from the second electrode by a certain distance, wherein thesecond circular electrode is concentric about the axis that isperpendicular to the plane defined by the first circular electrode andperpendicular to a plane defined by the second circular electrode; afirst high-resistance material inserted into a first linear cutcompletely through the second circular electrode, wherein the first cutproceeds from a top to a bottom of the second circular electrode suchthat the first cut is parallel to the axis; a first trigger installed atthe second electrode at an angle with respect to the firsthigh-resistance material; and a second high-resistance material insertedinto a second linear cut completely through the first circular electrodeand displaced approximately 180° relative to the first high-resistancematerial, wherein the second cut proceeds from a top to a bottom of thefirst circular electrode such that the second cut is parallel to theaxis.
 2. The rotary arc gap switch of claim 1, wherein either the firstor second high-resistance material comprises an alloy comprising ironand nickel or an alloy comprising iron and chromium.
 3. The rotary arcgap switch of claim 1, further comprising a second trigger installed atthe second electrode and displaced approximately 180° to the firsttrigger.
 4. The rotary arc gap switch of claim 3, wherein either thefirst or second high-resistance material comprises an alloy comprisingiron and nickel or an alloy comprising iron and chromium.
 5. The rotaryarc gap switch of claim 1, wherein the angle between the firsthigh-resistance material and the first trigger is equal to or greaterthan 30°.
 6. An electrode for a rotary arc gap switch, comprising acircular electrode concentric about an axis that is perpendicular to aplane defined by the circular electrode and containing a linear gapcompletely through the electrode and parallel to the axis, wherein thegap is filled with a high-resistance material.
 7. The electrode of claim6, wherein the high-resistance material comprises an alloy comprisingiron and nickel or an alloy comprising iron and chromium.
 8. Theelectrode of claim 6, further comprising a first trigger.
 9. Theelectrode of claim 8, wherein an angle between the high-resistancematerial and the first trigger is equal to or greater than 30°.
 10. Theelectrode of claim 8, wherein the first trigger comprises tungstencoated with teflon.
 11. The electrode of claim 8, further comprising asecond trigger.
 12. The electrode of claim 11, wherein the secondtrigger is placed on the electrode at approximately a maximum distancefrom the first trigger.